PLC loop checks, HMI graphics and alarm testing, proven point by point
Commissioning software for SCADA and telemetry where every instrument loop, PLC input and HMI graphic has to be individually proven before an asset is trusted to a control room.
A water or wastewater control system is only as good as its weakest instrument loop: every sensor, actuator and alarm has to be loop-checked from field device through the PLC or RTU to the SCADA HMI before an operator can trust what the screen is showing. Deskely holds every I/O point, loop and alarm in one register with the loop-check and control-system-acceptance gates built in.
- Assets
- Instrument loops, PLCs, RTUs, HMI graphics
- Test
- Loop check, FAT, SAT, alarm and comms testing
- Interface
- Field instruments and central SCADA/telemetry
- Gate
- Control system acceptance
Choose your project type
The problem
A control room screen is only as trustworthy as its last loop check, and a spreadsheet cannot show which of thousands of I/O points has actually been proven end to end.
A water or wastewater programme can involve thousands of individual instrument loops across dozens of sites, each one needing to be traced from the field device through cabling and the PLC or RTU to the correct HMI graphic and alarm before an operator can rely on it.
When loop check sheets, factory acceptance test records and site acceptance test results sit in a systems integrator's own project files, the client cannot confirm before go-live which loops are genuinely proven versus configured but never actually tested in the field.
Deskely tags every instrument loop, PLC I/O point and alarm individually, so control-system readiness is reported loop by loop instead of taken on trust from an integrator's completion statement.
Setting up the register
Instrument loops, I/O points and HMI graphics are tagged assets matched to the I/O schedule and cause and effect matrix.
I/O schedules, loop drawings and cause and effect matrices are parsed into a reviewed register, so every instrument, PLC I/O point and alarm carries its loop number, its expected range and its HMI graphic reference from day one.
Loop check templates, FAT and SAT sequences and alarm and interlock test templates are defined once per instrument type and instantiated across every loop, whether the programme has one site or two hundred.
Communications infrastructure — radio, GPRS or fibre links between outstations and the central SCADA — is held as its own asset type, so a comms fault is tracked separately from a field instrument calibration issue.
Execution
Loop checking, FAT/SAT and alarm testing are proven loop by loop before control-system acceptance.
Each loop is checked from the field device to the PLC input or output and confirmed correct on the HMI graphic, with simulated and live values captured against the specific loop rather than a batch sign-off for a whole panel.
Factory acceptance testing proves the control system logic and HMI configuration before delivery, and site acceptance testing then repeats the critical sequences on the installed system, with any discrepancy between the two logged against the loop.
Alarm and interlock testing confirms every safety-critical alarm reaches the correct operator screen and, where required, a telemetry alert, with vendor punch from the systems integrator logged at the specific loop or panel.
Control system acceptance and handover
Control system acceptance is signed from proven loops, not from an integrator's assurance that the configuration matches the design intent.
Control system acceptance draws on the same loop check, FAT and SAT records built during commissioning, so the evidence the client's controls engineer requires before accepting the system is an export rather than a re-test of everything from scratch.
The handover pack for the operations team includes as-built I/O schedules, cause and effect matrices and alarm configuration keyed to the loop register, giving operators and maintenance the exact record used to accept the system.
Every signature carries a name, role and timestamp, which is what the client's controls engineer and the operations team expect before a control system is declared live rather than provisionally commissioned.
The dossier
Point-by-point proof, not a claim that the screen looks right.
Control system acceptance is only as good as its weakest instrument loop. The dossier has to show every I/O point individually tested, every alarm rationalised rather than just configured, and every HMI graphic checked against the live plant it represents.
Point-to-point loop check sheet
Each field instrument or actuator signal is verified end to end from the field device through to the correct PLC input or output.
Completed for every I/O point before the PLC logic is enabled.
PLC logic and interlock function test record
Control logic, permissives and safety interlocks respond correctly to simulated and live input conditions.
Run once loop checks are complete, before the process is placed under automatic control.
HMI graphic verification record
Each HMI screen reflects live plant status accurately, with correct tag mapping, units and animation.
Checked against the live or simulated plant during SCADA commissioning.
Alarm rationalisation and priority sign-off
Alarms are configured with the correct priority and set point, with nuisance and duplicate alarms removed.
Reviewed before the control system is handed to the operations team.
Historian and trend verification record
Process data is captured, time-stamped and retained correctly in the historian for the tags configured.
Verified once the SCADA system is logging live plant data.
Control system acceptance certificate
Every loop, interlock, graphic and alarm has been individually proven, clearing the system for operational control.
Signed once all point-level tests are closed with no open punch.
How it runs
From I/O schedule to control system acceptance.
SCADA programmes reward a register that treats every loop as its own asset, because an unproven loop is invisible right up until the moment an operator relies on a reading that was never actually checked.
- 01
Model the system by loop
Instrument loops, PLC I/O points, HMI graphics and comms links modelled as assets tied to the I/O schedule.
- 02
Parse the control design
I/O schedules, loop drawings and cause and effect matrices drafted into a reviewed register with expected ranges attached.
- 03
Template loop, FAT and SAT tests
Loop check, FAT and SAT sequences defined once per instrument type, instantiated across every loop and panel.
- 04
Gate acceptance on proven loops
Control system acceptance reported from proven loop records, with punch tracked to closure per loop.
FAQ
Questions about SCADA and telemetry scopes.
Keep reading
Water and wastewater commissioning
The full sector view: clean and dirty water commissioning, MEICA, SCADA and the regulatory sign-off behind them.
Read moreITR records
Pre-commissioning checklists and wet-test records defined once per asset type and instantiated across every tank, pump and valve.
Read moreMaster data
Asset registers, tag lists and P&ID data held as one structured source instead of scattered contractor spreadsheets.
Read moreOther water and wastewater project types: Water treatment plant commissioning, Wastewater treatment plant commissioning, Desalination plant commissioning, Water and wastewater pump station commissioning, Service reservoir and distribution network commissioning, Sludge and biosolids treatment commissioning, Industrial water reuse and reclamation commissioning, Stormwater and flood defence commissioning, Package plant and brownfield upgrade commissioning.
